Synthesis of γ-N-modified 8-oxo-2'-deoxyguanosine triphosphate and its characterization

Simple and Easy Synthesis of γ-Amido-dNTPs in Water and Their Polymerase Reaction Properties

γ-Amido-modified 2'-deoxynucleoside triphosphates (dNTPs) and nucleoside triphosphates (NTPs) are becoming increasingly important as biological tools. We herein describe the simple and easy synthesis of γ-amido-dNTPs and -NTPs from commercially available corresponding dNTPs and NTPs in a one-pot reaction using water-soluble carbodiimide and ammonia solution. We examined the effects of synthesized γ-amido-dNTPs on the DNA polymerase reaction. The results obtained showed the incorporation of these derivatives into the DNA primer while maintaining nucleobase selectivity; however, their incorporation efficiency by DNA polymerase was lower than that of dNTP. This is the first study to demonstrate the successful synthesis of four sets of γ-amido-dNTPs and clarify their properties.

Development of MTH1-Binding Nucleotide Analogs Based on 7,8-Dihalogenated 7-Deaza-dG Derivatives

MTH1 is an enzyme that hydrolyzes 8-oxo-dGTP, which is an oxidatively damaged nucleobase, into 8-oxo-dGMP in nucleotide pools to prevent its mis-incorporation into genomic DNA. Selective and potent MTH1-binding molecules have potential as biological tools and drug candidates. We recently developed 8-halogenated 7-deaza-dGTP as an 8-oxo-dGTP mimic and found that it was not hydrolyzed, but inhibited enzyme activity. To further increase MTH1 binding, we herein designed and synthesized 7,8-dihalogenated 7-deaza-dG derivatives. We successfully synthesized multiple derivatives, including substituted nucleosides and nucleotides, using 7-deaza-dG as a starting material. Evaluations of the inhibition of MTH1 activity revealed the strong inhibitory effects on enzyme activity of the 7,8-dihalogenated 7-deaza-dG derivatives, particularly 7,8-dibromo 7-daza-dGTP. Based on the results obtained on kinetic parameters and from computational docking simulating studies, these nucleotide analogs interacted with the active site of MTH1 and competitively inhibited the substrate 8-oxodGTP. Therefore, novel properties of repair enzymes in cells may be elucidated using new compounds.